Organic field-effect transistor (OFET), Electrolyte-gated OFET, Electrochromic display, Active matrix display, Smart pixel, TECHNOLOGY, Chemical engineering, Chemical process and manufacturing engineering, Electrochemistry, TEKNIKVETENSKAP, Kemiteknik, Kemisk process- och produktionsteknik, Elektrokemi

Monolithic integration of an electrolyte-gated organic field-effect transistor (OFET) and an organic electrochromic pixel is reported. Thanks to its versatility, the polyanionic proton conductor poly(styrenesulfonic acid) (PSSH) can serve both as the gate “insulator” in OFETs and as the electrolyte in electrochromic display pixels. Employing identical materials in both the display cells and in the driver transistors is a necessary prerequisite to achieve robust displays possible to manufacture on flexible carriers using printing tools. Smart pixels combining depletion mode electrochemical transistors and electrochromic displays have been reported in the past. Here, an enhancement mode OFET as the driver enables relatively shorter updating times and much simpler addressing and updating schemes.